Apparatus for automatically controlling the feed of a material strip to a processing machine



June 1969 PTLUGINBUHL ETAL 3,451,188 APPARATUS FOR AUTOMATICALLYCONTROLLING THE FEED 0F A MATERIAL STRIP TO A PROCESSING MACHINE' FiledAug. 5, 1966 A Sheet June24, 1969 P. LUGINBUHL E APPARATUS FORAUTOMATICALLY CONTROLLING THE FEED OF A MATERIAL STRIP TO A PROCESSINGMACHINE Filed Aug. 5. 1966 Z of 2 Sheet NW mm u w O 0.9 I: & m

United States Patent US. Cl. 53-73 4 Claims ABSTRACT OF THE DISCLOSUREand when the first switch is closed and drives the motor of thepackaging machine, the other two switches are open.

The present invention relates toan apparatus for the automatic controlof the feed of a material stripto a processing machine.

Chocolate bars are normally enveloped air-tightinan aluminium foil andare subsequently provided with an additional paper envelope. The entirepackaging process is carried out fully automatically by a packagingmachine. There may arise the case where, e.g., owing to a failure of themachine or owing to the exhaustion of the aluminium-foil reserve,chocolate bars issue from the machine which has been provided with apaper envelope only. Since the absence of the aluminium foil cannot bedirectly detected from the outside, there exists the danger that suchbars will be put on sale, which is undesirable for hygienical andaesthetic reasons. The fat contained in the chocolate penetrates thepaper envelope after a certain time, so that the envelope will showgrease spots.

The invention has for object the creation of an apparatus, whichprevents the occurrence of the aforedescribed defects.

According to the present invention an apparatus for automaticallycontrolling the feed of a material strip to a processing machine, moreespecially the feed of an enveloping-material strip to a packagingmachine, comprises means influenced by objects fed to said apparatuscontrolling the advance of the material strip and means which effect thestopping of the machine when the controlling means detect an abnormalityin the advance of the material strip.

The invention will be described further, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a schematical side elevation of one form of apparatusaccording to the invention;

FIG. 2 is a section taken along the line II-II. in FIG. 1;

FIGS. 3 to 5 show different operational positions of three switchesprovided on the apparatus;

FIG. 6 shows, schematically, a side elevation of a second form ofapparatus according to the invention, and

I provided on the apparatus.

FIG. 7 illustrates a detail of the apparatus according to FIG. 6, with adiagram of the three electrical switches It The apparatus shown in FIG.1 includes a conveyor belt 1 having an aperture 2, into which engages asensor 3 which is linked to a pivotable pawl 4. The conveyor belt 1carries bar-shaped objects 5, e.g., chocolate bars, which are guidedover the aperture 2 to a first processing position, here not shown,where they are enveloped in a manner per se known in an aluminium foil6. This foil 6 is drawn off a storage roll 7, and is guided over a first7 guide roller 8 and a second guide roller 9 to a table 10.

The roller 9 is supported by hearing pins 26 which engage inserts 27,one at each end of the roller. The insert 27 hastwo parallel discs 27a,27b, between which engages the upper end of a lever 19. A continuouslyrotating feed roller 12, whose contact surface is flush with the surfaceof the table 10 is arranged in a slot 11 in the table. Directly abovethe fed roller 12 an applicator roller 14 is arranged on a pivotablymounted lever 13. The advance of the aluminium foil is effected byapplying the roller 14 against the roller 12, whereby the foil 6 locatedbetween the two rollers is moved in the direction of rotation of theroller 12.

The lever 13 is linked by a bar 15 with an arm 16a of a three-armedlever 16, which is pivotable about an axle 17. A roller 18 is mounted atthe end of the arm 16a,

and bears against the lever 19. A stationary rod 20 passes through aslot 19b in the lever 19, and the lever is held in the position drawn infull lines by a spring 21. The arm 16b of the lever 16 carries a roller22 hearing against a cam plate 23, which in turn is mounted on arotatable shaft 25. The shaft 25 further carries a cam disc 24, whichacts on an electrical switch C. The arm 16c of lever 16 cooperates onone hand with the pawl 4 and on the other hand actuates an electricalswitch B. A further electrical i switch A is actuated by the lever 19.As FIG. 3 shows,

the three switches A, B, C are arranged in parallel in the circuit of adrive motor of the packaging machine, which motor also drives the shaft25 and the roller 12. The switch A is open in its rest position, whilstthe switches B and C are closed in the rest position, as illustrated inFIG. 3, which corresponds to the position of the individual parts asshown in FIG. 1.

The apparatus operates as follows:

When the shaft 25 rotates, the lever 16 is pivoted in a clockwisedirection, as soon as the roller 22 passes from the range of the camplate zone having the larger radius R into the zone with the smallerradius r. This pivotal movement however can take place only if an object5 actuates the sensor 3, so that the pawl 4 releases the arm 16c. Thepivoting of the lever 16 initiates the following operations:

(a) The roller 14 is pressed against the roller 12 and the foil 6located between the rollers is advanced;

(b) Owing to the tractive force of the foil 6 the roller 9 is rotated.Since the roller 18 has ceased to support the lever 19 and the lattertherefore simply bears, under the traction of spring 21, with its edge19a on the insert 27, it is pivoted into the position drawn in chaindotted lines when the roller 9 with its insert 27 rotates, in whichposition it rests on two stops 28, 29. Owing to the rotation'of theinsert 27, the edge 19a of lever 19 rolls along the insert 27;

(c) The switches B and A are actuated, B is opened, A is closed. Therotation of the cam disc 24 further opens the switch C. FIG. 4 shows theposition of the three switches when the foil is advanced. The current issupplied to the driving motor through the switch A. The resetting of thelever 19 into its initial position is effected by the cam plate 23 onfurther rotation of the shaft 25, by means of lever 16 and roller 18.This also causes lever 19 to release the switch A, which returns intoits OFF position. Simultaneously the arm 16c releases the switch B,which returns into its ON position.

In the case where no object 5 moves along the conveyor belt 1 and overthe aperture 2, the pawl 4 prevents a pivotal movement of the lever 16.Switch B then remains effective and the machine continues to run.However, the foil 6 is not advanced.

In the case where, e.g., no foil remains, and thus no advance can takeplace, the roller 9 is not rotated. The lever 19 thus remains in itsposition drawn in full lines, even though it ceases to be supported bythe roller 18, since it rests with its edge 19a on the stationary insert27 under the traction of spring 21. The switch A is thus not activated,while the switches B and C are switched off. In this case, as shown inFIG. 5, all three switches are open and the machine is stopped.

The embodiment according to FIGS. 6 and 7 difiers from the embodimentdescribed in the foregoing only in that the switch A is actuated not bya lever 19 but by a generator 30 driven by the guide roller 9. As FIG. 6shows, the rotor of an electrical generator is linked with the guideroller 9; the latter supplies driving current to a relay 31 linked withan amplifier, which relay closes the switch A when energized by thegenerator 30. As FIG. 7 shows, the two other switches B and C areconnected in parallel to the switch A.

The mode of functioning is exactly the same as in the first form ofembodiment.

We claim:

1. An apparatus for automatically controlling the feed of a materialstrip to a processing machine, more especially the feed of anenveloping-material strip to a packaging machine, comprising anadvancing mechanism for the material strip, a three-armed leverinfluenced by objects fed to said machine which periodically executes apivotal movement, drive means for said lever, an arm of the levercontrolling said advancing mechanism, a first switch means having apivotable actuating lever releasable simultaneously with said advance,said actuating lever being pivoted by an advance movement of the strip,a second switch means actuated by said three-armed lever during itspivotal movement and a'third switch means actuated periodically by thedrive means of said lever, the whole being arranged in such a mannerthat the first switch means controlled by the actuating lever admitscurrent to the drive motor of the processing machine during a period inwhich the two other switch means have interrupted the supply of current.v

2. An apparatus according to claim 1 comprising a conveyor track and ablocking device controlled by the objects which prevents the pivotalmovement of the threearmed lever in the absence of an object at acertain region of a conveyor track.

3. An apparatus according to claim 1 in which a guide roller driven bythe material strip during its advance movement operates the actuatinglever of the first switch means.

4. An apparatus for automatically controlling the feed of a materialstrip to a processing machine, more especially the feed of anenveloping-material strip to a packaging machine, comprising anadvancing mechanism for the material strip, a three-armed levercontrolling said advancing mechanism, a first switch means, a second armof the lever actuating said first switch means to interrupt the supplyof current to a drive motor of the processing machine, a second switchmeans, drive means for said lever periodically actuating said secondswitch means to also interrupt the supply of current to said motor, aroller driven by the advance movement of the material strip, a currentgenerator connected to said roller, and third switch means actuated bysaid generator to ensure the fiow of current to the motor when said twoother switch means are open.

References Cited UNITED STATES PATENTS 2,668,404 2/1954 Barefoot 5355THERON E. CONDON, Primary Examiner. R. L. SPRUILL, Assistant Examiner.

